1. Field of the Invention
The present invention relates to a rotary positive displacement control system and apparatus, and particularly to a rotary positive displacement system and apparatus operating by ways of a periodic process of suction, expansion, compression, exhaust, and can be adapted to engines, vacuum pumps, internal combustion machines, compressors and rotary positive displacements.
2. Related Art
Generally, a concept of supercharging is that force air into an intake port of a sealing chamber which is equipped with multiple rotors rotating continuously and meshing with each other, in which air flows through a transmitting chamber and is compressed after rotation of the rotors and turns to be high pressure air, then air is discharged from the exhaust port. Due to such operation cycle, air is of high compression ratio. The character of high compression ratio can be used to apparatuses like engines, vacuum pumps, internal combustion machines and compressors and so on for improving working performance, lowering oil consumption, and reducing air pollution. Related structure of supercharging apparatus has been disclosed in numerous prior arts, such as U.S. Pat. Nos. 4,008,693, 4,321,897, 4,512,302, 4,813,388, 4,825,827, 5,329,900, 6,129,067, 6,481,410.
However, in prior arts there are still some disadvantages to the periodic operation process of suction, expansion, compression and exhaust. Those disadvantages lower the working performance of the apparatuses. That is, in prior arts, during periodic operation process, residual gases remain because of incomplete exhaust, even though the apparatus runs with a rotary positive displacement cannot avoid remaining residual gases. As a result, the apparatus cannot have a well efficiency in providing power and a longer lifespan. Moreover, power output of some apparatuses, such as engines, is transmitted through crankshafts, while the quality of the crankshafts will affect process of operation; if the crankshafts are of poor quality, the accuracy of dynamic balance is no longer accurate, which will cause unstable performance, shorten lifespan, and increase unnecessary power consumption.